Examples of proteolytic processing in various organs of our bodyEdit
- Renal proteins
In concern with the proteolytic processing with respect to kidney the human prorenin is considered. The proteolytic processing of human prorenin in renal tissues is discussed here. The mouse proprotein convertase also known as PC1 accurately cleaves the prorenin and generates active rennin. The human Proprotein Convertase also known as PC3 can also process the prorenin to generate rennin but not as efficiently as mPC1 does. This is because of the differences in the sequences of the carboxy terminus from PC1 to hybrid hPC1/mPC1. The cleavage of prorenin bay PC1 in humans takes place at a pair of basic amino acids by removal of 43 amino acid prosegment from the amino terminus of the it along with identification of a functionally important site in the hPC1. Also PC1 generates active rennin in other tissues like adrenal medulla and certain adrenal tumors. If human prorenin has either in Lys or Arg residues at the cleavage site then the hPC1 cannot generate active rennin.
- Blood protein
The Kell Blood Group Protein belongs to family of metalloendopeptidases. It’s a membrane glycoprotein which shares a pentametric zinc-binding consensus sequence. It conserves all the amino acids required for the endopeptidase activity. Kell Blood Group proteins have a homology with M13 family in which a disulphide bond is covalently linked to a protein named XK, this spans the membrane 10 times, whereas kell proteins is linked to XK present is fifth extracellular loop. Activation of endothelins and processing of bioactive peptides can be done by Kell proteins.
- Human Brain Spectrin
Fodrin, Human Brain Alpha Spectrin plays an important role in the nervous system yet its mechanism is not completely understood. Its isoforms are present within the cells and in some neurotransmitter neurons. It is proteolytically processed by the calcium dependent proteases. This processing of fodrin is a central molecular mechanism does the development of long term memory. Foldrin has a proteolytically hypersensitive site in its centre for cleavage. Calcium-dependent binding of calmodulin takes place at this site.